Buffer Tube Basics

[JoshNC]

Staking is OK but not absolutely necessary if everything is installed properly. It is the Military way of keeping people from taking things apart that they shouldn't be.

This is absolutely not true. I have personally had a properly torqued down castle nut loosen from my M16 after only 4 - 5 mags on auto. This happened to me more than once. The buffer tube WILL transfer some vibrational forces to the castle nut, which can cause it to loosen. This has happened to me with both a standard Colt M4 stock and with a Knights receiver endplate singlepoint. Staking helps prevent this.

[onmilo]

Sorry to hear that and,,,,OK.
If it makes you feel any better I do stake castle nuts because that is what I was trained to do.

I am a working gunsmith and was a small arms repairman during my time in the US Army.
I have repaired many, many M16 rifles, some M177 carbines, and civilian semi auto clone rifles from many different sources.
I have yet to repair the collapsing stock assembly of any rifle featuring this option where the fault could be directly traced to a commercial extension tube or an unstaked castle nut.
I still stand on my statement, though I really should have clarified that the statement is mainly intended for civilian semi automatic rifles, that staking of the castle nut is not absolutely necessary for safe and reliable functioning of the weapon.
All US MILITARY issue full auto and burst fire carbines have the castle nut staked as a matter of course, period, it is what is specified, there are no allowances for discrepency.

The most prevelent failure of collapsing stocks that I have seen is locking latch failure.
The staking of the latch nut does not appear to prevent this occurance either.

Not many civilian shooters have access to full auto M4 carbines or M16 rifles. There just aren't that many of them available and freely transferable on the market and those that are have the distinction of being extremely expensive now, almost too expensive to subject to the wear and tear of actual heavy duty firing.
I am sure most folks who have an interest in military weaponry would love to have that right to the full auto option allowed to them on an affordable basis but they are not.

Since you state that you are using a full auto M16 and not a CAR, M177, or M4 then it stands to reason that you, or someone else, installed that collapser stock as an add on right?
None of the posters here, myself included, have any proof or knowledge that your stock assembly was in fact, assembled correctly.

I did say and I quote: "Staking is not absolutely necessary if everything is installed correctly." Though my original statement was intended for civilian rifles I do feel it has merit when used in conjunction with full automatic rifles also.
The staking is applied to the castle nut to keep people from taking things apart that they should not be taking apart.
Unit level Armorers are not authorized to remove the stock assemblies from weapons, this is only done on a limited basis at level one depot repair and mainly preformed at level 2 depot repair.
Just the same, a police or paramilitary armorer should probably stake the castle nut if the weapons come from the source unstaked as a matter of course
and to eliminate any possible potential issues of liability and most certainly to eliminate complaining from the more gun saavy officers.


Your retort was thoughtful but it still hasn't altered my personal opinion on this subject.
If a shooter feels more comfortable with a staked castle nut, by all means stake the castle nut.
Because some manufacturers do not stake the castle nut does not automatically make their rifle crap unworthy of purchase or contemplation.

[Renegade]

I did say and I quote: "Staking is not absolutely necessary if everything is installed correctly." Though my original statement was intended for civilian rifles I do feel it has merit when used in conjunction with full automatic rifles also.
The staking is applied to the castle nut to keep people from taking things apart that they should not be taking apart.

My own experience I agree. I have a Full/Auto gun and I never stake it. Reason being I am frequently changing stocks and such and just do not do it. I have never had a problem in thousands of rounds.

I also agree the "locking latch failure" is most common. I do not have this problem anymore though since I no longer use the factory Colt stock.

[M-Forgery]

A tiny dab of blue Loctite keep castle nuts tight for me. A proper wrench will both provide proper torque when tightening and will also break blue Loctite when necessary to replace the receiver extension.

[M-Forgery]

If you all feel comfortable not staking a castle nut, great. To suggest it's the way to do things is unresponsible & ill informed. The mechanical engineers that put the recess in the caste nut, to allow metal from the staking process to push into the castle nut, ensuring it would not back out knew what they were doing.

This forum, tends to have a more proffessional/informed perspective than the usual www.anecdotal.crap

I have seen FACTORY assembled: HK, Colt, BM receiver extension tubes all come loose. If not for the staking the reciever extension tube would have backed off allowing the buffer detent to pop up rendering the weapon unusable. You can still fight with a wobbly stock, not a seperated one.

Cause: Poor assembly process. A castle nut should be torqued, backed off & retorqued 3x like a barrel nut & then properly staked in two positions. Tolerance stack will determine how tight the reciever extension tube (buffer tube improperly said) will fit in the lower reciever.

Point well taken and very well stated. I was speaking from a hobby aspect where the receiver extension may be removed, swapped, or replaced frequently as a rifle's configuration is changed. Once the final configuration is decided upon by the owner, by all means stake that castle nut.

[cmdecker]

I have a Noveske lower and want to install a UBR stock but need to remove the castle nut that has ben staked...how do I go about removing a castle nut that has been staked?

[markm]

I have a Noveske lower and want to install a UBR stock but need to remove the castle nut that has ben staked...how do I go about removing a castle nut that has been staked?

Either torque the mother off (this works if the stake job isn't deep) or dremel the stakings.

[JimmyB62]

I have a Noveske lower and want to install a UBR stock but need to remove the castle nut that has ben staked...how do I go about removing a castle nut that has been staked?

I've found that rather than just slowly applying force to the wrench, a series of short, sharp, pulls works better. It's a bit similar to the way an impact wrench breaks a nut loose. I've had good result with a block(magazine) and vice. It shouldn't take an excessive amount of force.

[onmilo]

Call me irresponsible and ill informed, I can take it.
Professional is spelled p-r-o-f-e-s-s-i-o-n-a-l.
To spell it any other way is ill informed.

An extension tube cannot become loose without the castle nut backing off first.
There is a tab on the endplate that butts up against the receiver and the tab fits into the milled keyslot on the extension tube which prevents the extension tube from turning in the receiver.
What can happen is the castle nut can back away from the endplate far enough to allow the bottom of the endplate to be pushed away from the receiver freeing the selector detent and spring which can cause the selector to pop free into the lower receiver and all kinds of fun and merryment ensues.

The engineers who designed the castle nut were also well aware of the meaning of the word 'redundency'.
Look it up.

[Iraqgunz]

First off, I am an armorer and am currently working in Iraq for a large PMC. I have quite a bit of weapons experience and have current certifications from Beretta, Barrett, Colt, Dillon, FN, Glock, Knights Armament, Remington and Sigarms. I have 9 years military experience in the US Army and Coast Guard.

Now to the subject at hand. I have never seen a Bushmaster carbine from the factory come with a staked locking collar. But, I have seen ALOT of them loosen during shooting, especially when firing in auto. All of the ones we have on contract are select fire guns. I have also seen bolt carrier keys that were allegedly torqued and staked come loose as well. So to say that there is no need to stake the collars is irresponsible and tells me that that individual doesn't care much about this weapons. There is a reason why the military does this. I have also seen lower receiver extensions that were put on and the collars tightened so much that the threads were stripped. As far as I am concerned Loc-tite is not an acceptable substitution.

I have no axe to grind with anyone here as I am a new member. But, I also know that there are alot of "experts" out there who have never used a weapon in the field and even fewer have done troubleshooting or repairs in the field.